shader noise on rest fields

[gonzzzo]

Hi everybody,

I would appreciate it if someone could clarify this issue.

I've been trying to rest the noise on a volume fluid.

The help card for the pyro solver says "that the dual rest fields create a rest2 field that is reset in a leapfrog fashion with the main rest field".

I can see them in the details view.

But when I render with noise there is no merge between 2 fields.

It just resets the noise at frame 53 (ups shouldn't it be 50) and restarts.

I've attached an example.

How to merge the 2 rest fields?

Or am I thinking totally wrong here?

Thanks

restfields.mov

[SpencerL]

Hi everybody,

I would appreciate it if someone could clarify this issue.

I've been trying to rest the noise on a volume fluid.

The help card for the pyro solver says "that the dual rest fields create a rest2 field that is reset in a leapfrog fashion with the main rest field".

I can see them in the details view.

But when I render with noise there is no merge between 2 fields.

It just resets the noise at frame 53 (ups shouldn't it be 50) and restarts.

I've attached an example.

How to merge the 2 rest fields?

Or am I thinking totally wrong here?

Thanks

Is the shader you are using calling in both rest fields and blending between the two? when using pyro it creates 2 rest fields "rest" and "rest2". In order for this to work properly, you can use the VEX Pyro shader which calls both of these rest fields. If you use a differnt shader, make sure you bring in both "rest" and "rest2" and use a mix to blend from one to the other, in your case every 50 frames.

[gonzzzo]

Is the shader you are using calling in both rest fields and blending between the two? when using pyro it creates 2 rest fields "rest" and "rest2". In order for this to work properly, you can use the VEX Pyro shader which calls both of these rest fields. If you use a differnt shader, make sure you bring in both "rest" and "rest2" and use a mix to blend from one to the other, in your case every 50 frames.

Got it! Thanks very much!

[gonzzzo]

It took me a while to figure this out so I'm attaching an image for whoever is trying to get this as well.

The highlighted nodes where added.

Also the display flag has to be on the pyrofields or what ever geometry containing the 2 restfields (check details view).

Thanks again to SpencerL for the tip

[gonzzzo]

.

[goshone]

I tried this setup on the billowy smoke shader, and still get some weird behavior. Are you animating your rest field blend?? I assume you are, but was wondering what your keyframes are. If your rest fields reset every 50 frames, let's say, do you blend from frame 25 to 50, or 25 to 75??? Does that question even make any sense?

I read thru this post

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=16117

Which had a lot of info on using the pyro shader, but I am interested in the billowy smoke shader, and more importantly, creating a custom shader that uses such rest fields. Does anyone have a good solution for adding this texture on smoke, and if so, please post a sample file.

Mine is attached.

dustPuff_v03.hip

[jingyisw]

hi,when i render fire sim  with pyro shader , at fire color  tab    i turn on the active noise toggle  , why  does the noise  not  move with the fire in the final image sequence ? Do you know that? 

[breadbox]

adding onto this topic,  I am trying to do something similar, use a dual rest pos in a "Billowy" shader which is by default only setup for a single rest position.

I wonder if its possible to copy an d paste the dual rest structure from the pyro into billowy?

 

I see that the output of the dualrestsolver is of type "struct" however what I need is a type Vec3 postion to enter into the billowy noise position. Is there a way to convert this dual rest so that the output can drive the noise position properly?

[Mikal]

Hey Breadbox

I'm sure you could grab the pyro dual rest nodes and put them into the billowy shader, although any exposed parameters should probably be re-created. 

If you've enabled dual rest fields, you will automatically have detail attributes available to you named (rest_ratio, and rest2_ratio) - which will help you blend the two rest fields together either in a shader or you could build a separate vector field if you wanted. 

I think... the formula is:

dualrest = (rest*rest_ratio)+(rest2*rest2_ratio)

If you pump the resulting dualrest vector field into the position parameter of a noise function - you should see the noise advect. Although one thing to remember is the advection strength you simmed the rest fields at, will determine the how closely the noise sticks to any smoke.

Cheers